Control system for oil-burners



C. B. BUERGER. CONTROL SYSTEM FOR OIL BURNERS. APPLICATION FILED JUNE 17. 1920.

Patentefi May 1141) 11921.

3 SHEETS-SHEET I.

INVENTOR.

@M @A @1424 BY $25M 7&1 A TTORNE Y.

C. B. BUERGER. CONTROL SYSTEM FOR OIL BURN ERS.

APPLICATION FILED JUNE 17' 1920.

Patented May M1) 1921,

s SHEETS-SHEET 2.

ILQWKSGSD INVENTOR.

BY m

A TTORNE Y.

C B. BUERGER.

CONTROL SYSTEM FOR OIL BURNERS.

APPLICATION FILED JUNE 17, 1920.

Patented May 1M), 1921.

3 SHEETS-SHEET 3.

N340 OJ.

' 211A TTORNEY.

CHARLES B. BUERGER, 0F PHILADELPHIA, PENNSYLVANIA, ASSIGNOR TO THE ATLANTIC REFINING- COMPANY, OF PHILADELPHIA, PENNSYLVANIA, A. COR- PORATION OF PENNSYLVANIA.

CONTROL SYSTEM FOR OIL-BURNERS.

ameos. I

Specification of Letters Patent.

Patented May 10 1921.

To aZZ whom it may concern:

Be it known that I, CHARLES B. BUERGER, a citizen oft-he United States, residing in the city and county of Philadelphia, State of Pennsylvania, have invented certain new and useful Improvements in Control Systems for Oil-Burners, of which the followin is a specification.

lily invention relates to a system for effecting automatic control of the rate of supply of fluid fuel and the rate of supply of air, oxygen orother material which supports the combustion of the fuel, in accordance.

with heat demand or requirements.

My invention resides in a system of the character referred to wherein the fuel, as fuel oil, is supplied under pressure, and preferably pre-heated, to burner structure, as so-called mechanical burners, the pressure of'the fuel being controlled in response to variations of a condition, as variation of steam pressure of a boiler, effected by combustion of the fuel; and, further, .wherein the supply or rate of delivery of the air, oxygen or other combustion supporting material is varied in accord with variations of pressure of the fuel and therefore in accord with variations in the rate of fuel supply.

My invention resides in thefeatures of construction and combination hereinafter described and claimed.

For an illustration'of one of the various forms my invention may take, reference is had to the accompanying drawings, in which:

Figure 1 is a diagrammatic view of a system embodying my invention.

Fig. 2 isa fragmentary side elevational view, on enlarged scale, of part of the apparatus involved in the system shown in Flg. 1.

Fig. 3 is a fragmentary plan view, on enlarged scale, of part of the apparatus involved in the system of Fig. 1.

Referring to Fig. 1, B and B are boilers or boiler structures such, for example, as may be employed forgenerating steam for steam power or any other purposes. From 4 the boiler structures extend pipes 1,. controlled by valves 2, delivering steam to the main steam header or pipe 3, by which the steam is delivered to the point of consumptron, the pressure in the steam system preferably being kept as near constancy as possible, but generally varying with variations in demand or load.

Burners 4, of suitable number and capacity, are employed for effecting combustlon of fluid fuel, such as fuel oil, delivered by the pipe 5 and from it passes into the branch pipes 6 controlled by valves 7.

The burners may be of any suitable type, such, for example, as those styled mechanical burners, such, for example, as are pro.- vided with means, as curved uide vanes or the like, for imparting rotatlon to the oil or fuel more effectively to subdivide or spray the same.

When fuel oil is employed, it may be stored in the reservoir or storage tank 8, from which it may be withdrawn through pipes 9 and 10, or either of them, controlled, respectively, by valves 11 and 12, intothe pipe 13, with which may be associated a pressure gage 14, and thence into either or both of the suction strainers 15 or 16, controlled, respectively, by valves 17, 17 and 18, 18. From the strainer or strainers the oil is delivered into the pipe 19, which may be provided with a pressure gage 20 and thermometer 21. The pipe 19 may be provided with a valve 22, which. when closed will force the oil to pass through the bypass 23 in which is connected a meter 24 controlled by the valves 25, 25. A valve 26 controls communication between the pipe 19 and the suction of the pump'end of the steam pump P, the engine end of which is operated by steam from any suitable source, as the main 3, delivered through the valve 27 and pipe 28. The-pump discharges the oil at higher pressure into the pipe 29, with which may be associated a pressure gage 30, and thence through the valve 31 into the oil heater H, the heating medium for which may be steam drawn from the header 3 through pipe 32 controlled by check valve 33, reducing valve 34 and hand valve 35, reducing valve 34 maintaining substantially constant steam pressure upon the heater H and therefore effecting substantially constant temperature within the heater, whereby the o l is heated to a predetermined substantially constant,

temperature. The heated oil is discharged from the heater H into the pipe 36, controlled by valve 37, and provided with thermometer 38 and pressure gage 39. The oil passes through the valve 40 through the strainer 41 and thence through the valve 42 to the pipe 43. From the pipe 43 extends a L pipe 43 and the aforesaid pipe 5 is the interposed pressure reducing-valve V, to the left of which the oil is under high pressure and to the right of which the oil is under reduced or low pressure, a gage 47 serving to indicate the pressure in the low pressure oil line 5.

The reducing valve V is mechanically actuated or controlled by the controller C responsive to steam pressure in the header 3.

and communicated to the controller C through the pipe 48 controlled by the valve 49.

The controller C may be of any suitable type or structure for moving the valve V toward closed position in response to rise in pressure in the steam header 3 and for moving it toward open position with decrease in pressure in the header 3. The controller C herein shown by Way of example, is, per se, not my invention.

Referring now to Fig. 2, the controller C' is shown as comprising a cylinder 50 in which is movable the piston 51 connected to the piston rod 52 pivoted at 53 to the lever 54 pivoted at 55 and having pivoted thereto at 56 the rod 57 pivoted at 58 to the arm 59 connected to the movable element of the valve V. Associated with the cylinder 50 is the member 60 in which is disposed a flexible diaphragm 61, or equivalent, to the under side of which is communicated the pressure within the header 3 through the aforesaid pipe 48. Disposed above the diaphragm 61 is one end of the arm 62 pivoted or fulcrumed at 63, a member 64 carried by the diaphragm 61 thrusting against the under side of the arm 62 at 65. Pivoted to the arm 62 at 66 is the valve rod 67 controlling suithaust of such fluid therefrom. The aforesaid medium is delivered under pressure through the pipe 69. The medium may be water under pressure, or it may be condensate or condensed steam under pressure of any suitable source of steam, for-example, the header 3. The water is delivered to the valve structure 68 through pipe 7 0 con-- trolled by valve 71; and the water or other medium is exhausted from the valve structure 68 through the pipe 72 into the waste pipe 73.

Attached to the piston rod 52 at 74 is the arm 75, to which is attached the down- \vardly extending rod 76, suitably guided at 77, 77 and having attached at its lower end a cord 78 passing over idler pulley 79 carried by the frame work and over the pulley 80 carried by the aforesaid arm 62 and carrying at its end the weight. 81. A second weight 82, adjustable along the arm 62, is attached to the cord 78, whereby as the piston rod 52 moves, the weight 82 is adjusted as to its position longitudinally of the arm 62 while the weight 81 always acts upon the arm 62 at the same point, to wit, the center of the pulley 80.

Returning to Fig. 1, 83 represents a pipe, flue or duct, closed at its one end at 84, into which there is forced at its left endair, oxygenor other combustion supporting material under pressure, the pressure being produced by pump, blower or any equivalent means, not shown. Within the duct 83 is disposed suitable throttling mechanism, as valve or damper structure A which controls the rate of flow of air or the like into the duct 83, which latter is connected to the right of the mechanism A through suitable connections with the combustion chambers,-

Referring to Figs. 2 and 3, the controller D will be observed to be in general similar to the above described controller C. It comprises the diaphragm 61 to the upper side of which is, communicated through the aforesaid pipe 85 the pressure of oil in the low pressure oil line 5. The diaphragm thrusts upon the arm 62 fulcrumed at 63, at At 66 there is pivoted to the \arm'62 the valve rod 67 controlling valve structure in the casing 68, such valve structure controlling delivery of water or other medium under pressure from the pipe 69 through pipe controlled by valve 71*, into the cylinder 50, and likewise controlling exhaust of water or other medium to the pipe 73 through the pipe 72. Movable in the cylinder 60- is the piston 51 secured upon the piston rod 52 to which is secured a member 7 5 attached to the rod 7 6 connected through the pivoted rod 7 8 to the carriage 7 9 rolling upon the beam or arm 62 and carrying the weight 82, whereby movement of the piston rod 52- adjusts the position of the weight 82 longitudinally of the arm 62.

As seen in Fig. 3, the member 7 5 has an arm 87 secured to the cable, cord or chain 88 passing over the idler pulleys 89, 89, and connected at its opposite ends to turn buckles or other suitable adjusting means 90, 90.

On the inside of the duct 83 are secured members 91, 91 serving as stops for the valve or damper members 92, 92 movable in unison within the duct 83 for throttling the same to greater or less extent. The damper members 92 are secured upon rotatable shafts 93, whose ends extend to the exterior of the duct 83. On one end of each of the shafts 93 is secured an arm 94, the arms 94 being coupled by the rod 95 pivoted to the arms 94 at 96, 96, whereby the damper members 92 are caused to move in unison.

Secured upon each of the shafts 93 outside of the duct 83 is a wheel, disk or equivalent member 97, to which is-secured a cam or equivalent member 98 having the surface 99, such as a cam surface or other surface of varying radius as regards the axis of rotation of the damper members 92. To the cam members 98 are secured at 100 the ends of cords, cables, chains or the like 101 attached at their other ends to the aforesaid turnbuckles 90.

It accordingly will be seen that as the piston rod 52 moves, the cord 88 will pull upon one or the other of the'cam members through the cords 101 lying upon or in grooves in the cam surface 99, whereby a given extent of rectilinear movement on the part of the piston rod 52 imparts a disproportionate rotative movement to the damper members 92, whose closed position is indicated by the dotted lines 102 and whose fully open position is indicated by the dotted lines 103.

The manual controller and indicator M, Fig. 3, comprises the wheel 104 around which is wrapped the cord, cable or chain 105 passing over idler pulleys 106 and connected to the turn buckles or equivalent devices 107 with the cords, cables or chains 108 attached at their other ends to the cam members 98 at 109, the cords 108 and 101 being disposed side by side upon the cam surfaces 107, as in parallel grooves. Upon the wheel 104, or any suitable member rotating therewith, may be provided a scale 110, with which co-acts the stationary pointer 111, the scale being marked in any suitable units, as extents of opening of the dampers 92, rates of flow of air or other combusti on supporting medium, or other suitable units.

As the dampers 92 are operated by the controller D as above described, motion is communicated to the wheel 104 through the cords 108 and 105, the structure then serving as indicating means.

However, if the controller D is out of service or disconnected from the damper structure, rotation of the wheel 104 by the hand wheel 112 serves to adjust the dampers 92 to different positions, the position of the dampers again being indicated by the scale 110 and pointer 111.

The operation is as follows:

The pump P puts the oil in pipes 29 and 43 under suitably high pressure, preferably substantially constant and not less, for example, than 150 pounds per square inch, the pressure increasing, according to demands for oil, to suitably higher values, for example, 300 pounds per square inch, more or less.

In the heater H the temperature of the fuel, as oil, is raised to any suitable extent, for example, 250 degrees Fahrenheit, more or less, in the case of so-called fuel oil.

When the loadupon the boilers increases, that is, when the steam consumption increases, or when for any other cause the pressure within the steam header 3 falls, the pressure on the under side of the diaphragm 61 of the controller C correspondingly decreases, causing decrease in upward pressure by the diaphragm structure upon the under side of the beam or arm 6.2, which arm, for a given position of the weight 82, then descends, pulling downwardly upon the valve rod 67, causing opening of the valve structure and admission of more water or other medium into the cylinder 50 from the pipe 69, causing ascent of the piston 51 and movement of the valve arm 59 in counterclockwise direction, as viewed in Fig. 2, increasing the opening of the valve V and thereby increasing the oil pressure in' the low pressure oil line 5, this resulting in turn in delivery of greater quantity of oil to the burners, a condition suitable for increased combustion and therefore generation of greater amount of steam or increase in steam pressure in. the header 3.

The compensating weight 82 is so related to and actuated by the mechanism of the controller C that relatively small fluctuations in pressure in the header 3 will accomplish suitably great movements of the valve V to effect suitably great change in pressure in the low pressure oil pipe 5. The con troller C is of the so-called compensating type, whereby hunting or wide fluctuations or excessive movement of the valve V will be prevented.

The pressure of the oil in the pipe 5 may range, for example, from 40 to 250 pounds per square inch, and such is the pressure of the oil delivered to the burners, the quantity of oil delivered varying with the pressure in the pipe 5, which pressure in turn varies with the pressure of the steam in the header 3.

While increase of oil or fuel is essential for increase in amount of heat delivered to the boiler or other structure or device, increase in amount of combustion supporting material, as air, is also essential properly to burn the oil to procure maximum or most economical heat production, it being desirable to supply air at a rate directly proportional to the rate of delivery of oil at or to the burners, the amount of air being further preferably slightly in excess of sufliciency for complete combustion of the oil.

So to control the air or equivalent the controller D is employed, which is responsive to the variations of oil pressure in the pipe 5, these variations being relatively of greater extent than the variations of steam pressure in the header 3.

As the pressure in the steam header 3 falls, the valve V is opened the wider, as stated, causing increase of oil pressure in the pipe 5. Such increase of pressure causes increase in downward thrust of the diaphragm 61 upon the beam 62 to the left of its fulcrum 63, in opposition to the weight 82, causing downward movement of the valve rod 67, causing admission of more water or other medium from pipe 69 into cylinder 50*, causing the piston rod 52 to move toward the right, Fig. 2, or upwardly, as viewed in Fig. 3. In consequence the damper members 92 are moved in clockwise direction, as viewed in Fig. 3, increasing the opening through the damper structure and allowing more air to pass into the duct 83 and from it into the combustion chambers, whereby as the amount of oil delivered to the burners is increased in response to decrease in steam pressure in the header 3, more air is admitted or delivered to the combustion chamber for effecting combustion of the increased amount of oil.

In order that the rate of supply of air shall be directly proportional to the rate of supply of oil to the burners, the cams 98, or their equivalent, are provided to effect movements of the damper 92 disproportionate to the extent of movement of the piston rod 52*, the damper movement being necessarily disproportionate in order that, in conformity with the law of flow of air or the like through ducts and to compensate or allow for other variables, the rate of flow of air shall be proportional to the pressure in the pipe 5, that is, proportional to the amount of oil delivered to the burners. The shape of the cam surfaces 99 will therefore be different for different installations and under different circumstances. They are experimentally determined by the engineer for each installation or for each set of circumstances. And the same is true of any equivalent devices causing movement of the damper structure disproportionate to the movement of the piston rod 52.

It will be understood that the structure described operates in reverse sense upon increase of pressure in header 3. That is, as the pressure in the header 3 increases, the oil pressure in pipe 5 decreases, thus decreasing the amount of oil fed to the burners, and the amount of air or equivalent is proportionately decreased.

While I have hereinbefore described a forced draft system, in that the air or equiva- 80 lent is forced under pressure into the combustion chambers, it willbe understood that the supply of air or equivalent may be similarly controlled by controller D and damper or valve structure A by locating the latter, in the case of a natural draft system, in the main breeching between any boiler or combustion chamber and the chimney or smoke stack; and in the case of employment of induced draft locating the damper structure between the draft inducing fans and the boiler or boiler furnace; and in the case of employment of both a forced and in duced draft, the damper structure is preferably located, as herein illustrated, in the I(duct 83 in advance of the combustion chamers.

While my invention has been described from the aspect of its preferred use, to wit, in connection with steam boilers, it will be understood that it may be used for any other suitable or desired purpose, the controller C responding to variations in any condition, as pressure, temperature, etc., dependent upon the fuel consumption.

While the controller C responds more immediately to change in pressure in the header 3, it responds, in effect, to changes in fuel demand or requirement and fuel consumption. V

The amount of air or other combustion supporting medium may be varied by any suitable means or mode of operation, as by employing the controller D, or its equivalent, for controlling the speed of the air fan 115 or pump which causes the forced or induced draft, or in any other way controlling the rate of supply of air or equivalent.

What I claim is:

1. The combination with a burner, of 120 means for supplying oil thereto under varying pressure, a duct, throttling structure therein controlling the supply of combustion supporting medium, means responsive to said variations in oil pressure, and acam oil supplied to said burner.

2. The combustion with a burner, of means for supplying oil thereto under varying pressure, a duct, rotatable damper structure therein controlling supply of combustion supporting medium, means responsive to said variations in oil pressure, and a cam controlled by said pressure responsive means and controlling extent of rotation of said damper structure, whereby said combustion supporting medium is supplied at a rate directly proportional to the rate of oil supplied to said burner.

In testimony whereof I have hereunto affixed my signature this 10 day of June,

GHARLES B. BUERGER. 

